AirDrop
Developer(s)Apple Inc.
Initial releaseJuly 20, 2011; 12 years ago (2011-07-20)
Operating systemiOS 7 and later
iPadOS
OS X 10.7 Lion and later
visionOS
PlatformiPhone 5 and later
iPad (4th generation) and later
iPad Mini (1st generation) and later
iPad Pro (1st generation) and later
iPod Touch (5th generation) and later
MacBook Pro
MacBook Air
MacBook
iMac
iMac Pro
Mac Mini
Mac Studio
Vision Pro
TypeUtility software
LicenseBundled proprietary software
WebsiteAirDrop on iOS and iPadOS
AirDrop on macOS

AirDrop is a proprietary wireless ad hoc service in Apple Inc.'s iOS, macOS, and visionOS operating systems, introduced in Mac OS X Lion (Mac OS X 10.7) and iOS 7,[1] which can transfer files among supported Macintosh computers and iOS devices by means of close-range wireless communication.[1] This communication takes place over Apple Wireless Direct Link 'Action Frames' and 'Data Frames' using generated link-local IPv6 addresses instead of the Wi-Fi chip's fixed MAC address.[2]

Prior to OS X Yosemite (OS X 10.10), and under OS X Lion, Mountain Lion, and Mavericks (OS X 10.7–10.9, respectively) the AirDrop protocol in macOS was different from the AirDrop protocol of iOS, and the two were therefore not interoperable.[3] OS X Yosemite and later support the iOS AirDrop protocol, which is used for transfers between a Mac and an iOS device as well as between two 2012 or newer Mac computers, and which uses both Wi-Fi and Bluetooth.[4][5] Legacy mode for the old AirDrop protocol (which only uses Wi-Fi) between a 2012 or older Mac computer (or a computer running OS X Lion through OS X Mavericks) and another Mac computer was also available until macOS Mojave.[5][6]

Apple reveals no limit on the size of the file which AirDrop can transfer. However, some Apple users have indicated that oversized[vague] files are almost impossible to transfer, with a high probability of failure.[citation needed]

Routine

iOS

On iOS 7 and later, AirDrop can be accessed by either tapping on Settings > General > AirDrop,[7] or via the Control Center.[8] Both Wi-Fi and Bluetooth are automatically switched on when AirDrop is enabled as they are both utilized.[8] NFC can also be utilized to initiate a transfer in iOS 17 or later. Options for controlling AirDrop discovery by other devices include:[8]

In iOS 16.2 or later, the Everyone option reverts to Contacts Only after 10 minutes.

If an application implements AirDrop support, it is available through the share button. AirDrop is subject to a number of restrictions on iOS, such as the inability to share music or videos from the native apps.[9]

macOS

On Macs running OS X 10.7 and greater, AirDrop is available in the Finder window sidebar.[10] On Macs running OS X 10.8.1 or later, it can also be accessed through the menu option Go → AirDrop or by pressing ⇧ Shift+⌘ Cmd+R.[11]

AirDrop must be selected in a Finder window sidebar to be able to transfer files. Furthermore, files are not automatically accepted, but instead give a prompt asking to receive or decline the file sent.

System limitations

Transfer between two iOS devices

Running iOS 7 or later:[8]

AirDrop can be enabled unofficially on iPad (3rd generation) by jailbreaking the device and installing "AirDrop Enabler 7.0+" from Cydia. This procedure is not endorsed by Apple.

Transfer between two Mac computers

Running OS X Yosemite (10.10) or later:[5]

Transfer between a Mac and an iOS device

To transfer files between a Mac and an iPhone, iPad or iPod touch, the following minimum requirements have to be met:[12] All iOS devices with AirDrop are supported with iOS 8 or later:[8]

Running OS X Yosemite (10.10) or later:[5]

Bluetooth and Wi-Fi have to be turned on for both Mac and iOS devices. (Both devices are not required to be connected to the same Wi-Fi network.)

Security and privacy

AirDrop uses TLS encryption over a direct Apple-created peer-to-peer Wi-Fi connection for transferring files.[13] The Wi-Fi radios of the source and target devices communicate directly without using an Internet connection or Wi-Fi Access Point.[13]

The technical details of AirDrop and the proprietary peer-to-peer Wi-Fi protocol called Apple Wireless Direct Link (AWDL) have been reverse engineered[14] and the resulting open source implementations published as OWL[15] and OpenDrop.[16]

During the initial handshake devices exchange full SHA-256 hashes of users' phone numbers and email addresses, which might be used by attackers to infer the phone numbers and in some cases email addresses themselves.[17] In 2024, The Beijing Municipal Bureau of Justice claimed that following complaints from the public about "anonymous dissemination of inappropriate messages" in public places using AirDrop, a forensic institute in Beijing was commissioned to analyze iPhone's encrypted device logs. A rainbow table correlating phone numbers and email accounts was created during investigation, and has "effectively assisted the police in identifying several suspects" involved in such cases.[18][19][20]

Researchers at the Technische Universität Darmstadt stated that Apple knew that AirDrop users could be identified and tracked as early as 2019 and did not implement a proposed fix in 2021.[21]

Use in protests

Following the 2022 Beijing Sitong Bridge protest, users in China used AirDrop to distribute similar protest posters and slogans.[22][23] Apple reportedly limited the AirDrop function in China just weeks before 2022 COVID-19 protests in China.[24][25][26] The AirDrop restrictions triggered a hunger strike at Apple's headquarters.[27]

Incidents

There have been numerous reported cases where iOS device users with AirDrop privacy set to "Everyone" have received unwanted files from nearby strangers; the phenomenon has been termed "cyber-flashing."[28][29] As of iOS 16.1.1, Apple has silently replaced the "Everyone" mode with "Everyone for 10 minutes" for users in China, which automatically reverts back to contacts only after time elapses. After it was discovered, Apple stated that this feature was intended to reduce unsolicited content, and would become available worldwide in a future update. It did not comment upon the timing of the change or why it is initially limited to China, with reports suggesting that the limitation was implemented due to the Beijing Sitong Bridge protest.[30][31]

In March 2022 a flight between Seattle and Orlando was detained on the runway at Orlando International Airport until police decided a hijack threat was "not credible", after 10-year-old child onboard the plane AirDropped a threat to another passenger, who alerted the crew.[32]

In May 2022, an AnadoluJet flight between Israel and Turkey was deboarded after Israeli users used AirDrop to share pictures of a Turkish airline crash, leading to at least one injury to a passenger. After a search of the luggage, the flight was reboarded and resumed its trip some hours later.[33]

In July 2022, an 18-year-old Spanish man flying from Rome to Alicante, airdropped some pictures of skulls and a generic menace in Amharic to some of the passengers, before take off. As the crew was informed and the captain asked for police intervention, the flight left with a two-hour delay and the young man was charged with procuring an alarm.[34]

In late August 2022, a man on an airplane that was taxiing for take off AirDropped nude photos of himself to others on the Southwest Airlines flight from Houston to Cabo San Lucas. When a passenger reported this to the flight crew, the pilot announced that if this didn't stop he would return to the gate, which would ruin their vacations, and the activity stopped.[35][36]

See also

References

  1. ^ a b Nations, Daniel. "What Is AirDrop? How Does It Work?". About.com. Archived from the original on May 9, 2016. Retrieved January 12, 2014.
  2. ^ Stute, Milan; Kreitschmann, David; Hollick, Matthias (2018). "One Billion Apples' Secret Sauce". Proceedings of the 24th Annual International Conference on Mobile Computing and Networking. pp. 529–543. arXiv:1808.03156. doi:10.1145/3241539.3241566. ISBN 9781450359030. S2CID 51953349.
  3. ^ Etherington, Darrell (September 17, 2013). "Apple iOS 7 Review: A Major Makeover That Delivers, But Takes Some Getting Used To". TechCrunch. AOL. Archived from the original on October 8, 2016. Retrieved October 3, 2013.
  4. ^ Jason (June 23, 2014). "iOS 8 and OS X Yosemite Preview: AirDrop finally works across iOS and Mac". iPhone Hacks. Archived from the original on August 20, 2016. Retrieved October 14, 2015.
  5. ^ a b c d "Use AirDrop to send content from your Mac". Apple Inc. September 30, 2015. Archived from the original on November 24, 2021. Retrieved October 14, 2015.
  6. ^ "Can not connect my 2 macs with AirDrop - Apple Community". discussions.apple.com. Archived from the original on August 3, 2020. Retrieved October 4, 2020.
  7. ^ "Two Easy Ways to Access AirDrop in iOS 11". iDrop News. December 4, 2017. Archived from the original on April 8, 2019. Retrieved December 5, 2017.
  8. ^ a b c d e "Share content with AirDrop from your iPhone, iPad, or iPod touch". Apple Inc. July 23, 2015. Archived from the original on May 27, 2020. Retrieved October 14, 2015.
  9. ^ "AnyDrop enables you to Send/Receive any file including Music using AirDrop - iOS Hacker". iOS Hacker. March 24, 2014. Archived from the original on January 21, 2021. Retrieved October 14, 2015.
  10. ^ Rawlinson, Nik (September 29, 2011). "How to use OS X Lion AirDrop - CNET". CNET. CNET. Archived from the original on April 13, 2019. Retrieved October 14, 2015.
  11. ^ "OS X Automation Workshop: Sharing Content Locally". Mac OS X Automation. Archived from the original on March 4, 2016. Retrieved October 14, 2015.
  12. ^ "OS X Yosemite: supported devices for Handoff, Instant Hotspot, Phone Calling, SMS, and AirDrop". Apple. Archived from the original on February 19, 2015. Retrieved October 14, 2015.
  13. ^ a b "iOS Security - iOS 11" (PDF). Apple. January 2018. Archived (PDF) from the original on February 20, 2020. Retrieved March 11, 2018.
  14. ^ Milan Stute; Sashank Narain; Alex Mariotto; Alexander Heinrich; David Kreitschmann; Guevara Noubir; Matthias Hollick (2019). A Billion Open Interfaces for Eve and Mallory: MitM, DoS, and Tracking Attacks on iOS and macOS Through Apple Wireless Direct Link. 28th USENIX Security Symposium (USENIX Security '19). Archived from the original on November 24, 2021. Retrieved May 20, 2019.
  15. ^ Milan Stute. "OWL: An open Apple Wireless Direct Link (AWDL) implementation written in C". GitHub. Archived from the original on July 21, 2019. Retrieved May 20, 2019.
  16. ^ Milan Stute; Alexander Heinrich. "OpenDrop: An open Apple AirDrop implementation written in Python". GitHub. Archived from the original on June 14, 2019. Retrieved May 20, 2019.
  17. ^ Goodin, Dan (April 24, 2021). "Apple's AirDrop leaks users' PII, and there's not much they can do about it". Ars Technica. Archived from the original on April 24, 2021. Retrieved April 24, 2021.
  18. ^ 快速锁定苹果手机“隔空投送”不当信息发送源,司法鉴定所突破技术难题 [Quickly Identifying the Source of Inappropriate Information Sent via Apple iPhone's AirDrop, Forensic Institute Breaks Through Technical Challenges]. The Paper. Retrieved January 8, 2024.
  19. ^ "Judicial expertise: Judicial expertise unveils the mystery of anonymous transmission via AirDrop" 司法鉴定:司法鉴定揭开“隔空投送”匿名传输的神秘面纱. Beijing Municipal Bureau of Justice. January 8, 2024. Archived from the original on January 9, 2024. Retrieved January 9, 2024.
  20. ^ "China Says It Cracked Apple AirDrop to Identify Message Sources". Bloomberg News. January 9, 2024. Retrieved January 9, 2024.
  21. ^ "Apple knew AirDrop users could be identified and tracked as early as 2019, researchers say". CNN. January 12, 2024. Retrieved January 13, 2024.
  22. ^ Kubota, Yoko (June 8, 2023). "Apple's AirDrop in the Crosshairs of China's National-Security Crackdown". The Wall Street Journal. ISSN 0099-9660. Retrieved June 9, 2023.
  23. ^ Cheung, Rachel (October 19, 2022). "Anti-Xi Jinping Posters Are Spreading in China via AirDrop". Vice News. Retrieved October 19, 2022.
  24. ^ Gilchrist, Karen (November 30, 2022). "Apple limited a crucial AirDrop function in China just weeks before protests". CNBC. Retrieved December 1, 2022.
  25. ^ Biron, Bethany. "Apple restricted AirDrop capabilities in China ahead of anti-government protests, leaving dissenters without key communication tool as demonstrations spread". Business Insider. Retrieved December 1, 2022.
  26. ^ Best, Paul (November 27, 2022). "Apple restricts AirDrop file-sharing in China that protesters have used". FOXBusiness. Retrieved December 1, 2022.
  27. ^ Allen-Ebrahimian, Bethany (December 6, 2022). "Chinese activists stage hunger strike outside Apple's California headquarters". Axios. Retrieved December 31, 2022.
  28. ^ Sarah Bell (August 13, 2015). "Police investigate 'first cyber-flashing' case". BBC News. Archived from the original on July 17, 2018. Retrieved June 21, 2018.
  29. ^ Harris, Harry (September 1, 2018). "Oakland-Maui flight: Pepper spray emergency follows disturbing photo". East Bay Times. Archived from the original on September 3, 2018. Retrieved September 3, 2018.
  30. ^ Gurman, Mark (November 10, 2022). "Apple Limits iPhone File-Sharing Tool Used for Protests in China". Bloomberg News. Retrieved November 10, 2022.
  31. ^ "Apple hobbled a crucial tool of dissent in China weeks before widespread protests broke out". Quartz. November 27, 2022. Retrieved November 28, 2022.
  32. ^ Galbraith, Alex (March 7, 2022). "Hijacking feared on flight to Orlando due to child's AirDrop prank". Orlando Weekly. Retrieved March 9, 2022.
  33. ^ None, None (May 10, 2022). "Israel: Turkish flight aborted as passengers get plane crash pics". BBC. Retrieved May 10, 2022.
  34. ^ "Messaggi di morte ai passeggeri, denunciato un 18enne per procurato allarme - Cronaca". Agenzia ANSA (in Italian). July 23, 2022. Retrieved July 24, 2022.
  35. ^ Bartiromo, Michael (August 31, 2022). "Pilot scolds Southwest Airlines passenger for allegedly AirDropping 'naked pictures' to entire plane". The Hill. Retrieved September 2, 2022.
  36. ^ Williams, David (September 2, 2022). "Southwest Airlines passenger AirDrops nude photo to other fliers". CNN. Retrieved September 2, 2022.